IAfter years of study and research, Helen Purdy Beale seemed on track in 1925 to become the first woman to graduate from Cornell University’s Department of Plant Pathology. Her final hurdle was getting the approval of her advisor Herbert Whetzel, who without her knowledge had prevented previous PhD students from earning PhDs because overqualified women could not be hired at agricultural research stations. True to form, Whetzel told Beale that her thesis could not be accepted and returned it, heavily marked in red ink. Beale threw the pages in his face and shouted, “You showed the devil’s claws!” and stormed according to a report by the virologist Karl Maramorosch. Beale received her PhD from Columbia University in 1929 and changed the course of plant virology with her work on Tobacco Mosaic Virus (TMV).
TMV wasn’t discovered until the late 19th century when chemist Adolf Mayer noticed that some tobacco plant leaves developed multi-colored spots and eventually shrank. Viruses were little known at the time, also because, unlike bacteria, they could not be seen with a light microscope. Mayer and other scientists attributed the condition to parasites, enzymes, or other substances they could not characterize in the plants, and could only diagnose TMV using the rudimentary technique of studying the symptoms of diseased plants. Beale set out to change that.
After graduating from Columbia, Beale returned to the Boyce Thompson Institute (BTI) in Yonkers, New York, where she had previously worked as a plant pathologist for several years. She postulated that a substance in animal serum – now known as an antibody – could be used to study plant viruses. Indeed, Beale found that the serum from rabbits injected with TMV-infected sap could then be mixed with sap samples from other plants to test whether they were also infected: only TMV-infected sap would produce a severe precipitate form (made from antibody) -bound virus) when mixed with serum. Different species of plants infected with the virus produced similar rainfall, indicating that the disease was not caused by a defect in the plants themselves, but was caused by an infectious agent. Beale then found that precipitate formation was specific to TMV and developed assays to determine virus concentration – methods that were among the earliest serological techniques in virology.
But Beale’s work went largely unnoticed for at least 30 years. Texas A&M University virologist Karen-Beth Scholthof, who wrote about Beales’ contributions in the field and describes her as the “mother of plant virology and serology,” notes that plant pathologists are late in using the tools and methods of the early 20th We used the 19th century as we did in the 1960s before rediscovering Beale’s experiments and using their assays, the principles of which are still used today. Frederick Charles Bawden, a plant pathologist, wrote in 1970: “I am still puzzled by how it was that so many virus workers were reluctant to use these invaluable techniques for a long time. In retrospect, it is very evident that they were even more valuable than those of us who used them. “
According to Scholthof, last year’s rapid COVID-19 test developments are due to Beale’s fundamental ideas a century ago. “Then and now, serology is really important to learn more about the biology of these viruses, where they are in cells, and to get a quick diagnosis,” she says.
Beale stayed with BTI for several decades and after her retirement compiled a 1,500-page bibliography with more than 29,000 references on plant virology. She died in 1976. She Ridgefield Press Obituary described her as “steadfast, funny and persistent”.